This project focuses on identifying and characterizing genes that extend life span (LAG's) in Drosophila melanogaster. The main tool is a set of 120 recombinant inbred (R1) lines derived from artificially selected long-lived and control stocks. Specific aims are (1) To test the hypothesis that LAG's pleiotropically affect other characters, including fertility and metabolic rate; (2) To execute fine-scale mapping and characterization of four QTL's identified on chromosomes 2 and 3, using single-nucleotide polymorphisms (SNPs); (3) To screen for point mutations and P-factor insertions that specifically after survival at the oldest ages; (4) To develop stocks for future research, including new RI's and lines that can reliably recover from freezing. Notable features of the proposed experiments are: (1) RI's derived from long-lived stocks are a unique and unusually valuable resource that took 4 years to construct; (2) The proposed research is a collaborative effort involving labs at 4 universities, (3) Experiments will be done on a large scale; the PI's lab routinely executes survival experiments with 100,000 flies; (4) It is important to study the RI's as soon as possible, because large sets of inbred lines tend to degenerate over time, due to the accumulation of new mutations and rare contamination; (5) Development of freeze-resistant flies is a high risk project that has the potential to revolutionize Drosophila research. Health relevance: It is important to test the pleiotropy hypotheses because they imply that interventions to extend life span my have deleterious effects early in life.